问题
Suppose we have a list L. The cartesian product L x L could be computed like this:
product = [(a,b) for a in L for b in L]
How can the cartesian power L x L x L x ... x L (n times, for a given n) be computed, in a short and efficient way?
回答1:
Using itertools.product():
product = itertools.product(L, repeat=n)
where product is now a iterable; call list(product) if you want to materialize that to a full list:
>>> from itertools import product
>>> list(product(range(3), repeat=2))
[(0, 0), (0, 1), (0, 2), (1, 0), (1, 1), (1, 2), (2, 0), (2, 1), (2, 2)]
来源：https://stackoverflow.com/questions/14615595/python-shortest-way-to-compute-cartesian-power-of-list